Radio communication system, small cell base station, radio terminal, transmission power control method, and allocation control method

摘要

A radio communication system wherein a femto cell base station (100a) is located in a macro cell (MC1) and a radio terminal (200a) is connected to the femto cell base station (100a) and wherein the femto cell base station (100a) or radio terminal (200a) controls, based on a propagation loss between the radio terminal (200a) and a macro cell base station (300a) existing in the neighborhood of the radio terminal (200a), the transmission power of a radio signal to be transmitted from the radio terminal (200a) to the femto cell base station (100a).

主权项

1. A small cell base station that forms a small cell smaller than a large cell formed by a large cell base station and that is installable in the large cell, comprising:
a transmission power control unit configured to control transmission power of a radio signal transmitted from a radio terminal connected to the small cell base station to the small cell base station, based on large cell-side propagation loss indicating propagation loss between the radio terminal and the radio terminal's neighboring large cell base stations, wherein the transmission power control unit controls the transmission power, based on small cell-side propagation loss indicating propagation loss between the radio terminal and the small cell base station connected to the radio terminal, in addition to the large cell-side propagation loss, and comprises: a reference value setting unit configured to set a transmission power reference value, which serves as a reference of the transmission power, by using the small cell-side propagation loss; an adjustment value setting unit configured to set a transmission power adjustment value for adjusting the transmission power by using the large cell-side propagation loss; and a transmission power determination unit configured to determine the transmission power by using the transmission power reference value and the transmission power adjustment value, wherein the adjustment value setting unit sets the transmission power adjustment value such that the transmission power is reduced as the large cell-side propagation loss is small, and the transmission power is increased as the large cell-side propagation loss is large.